Question

I found this regex that works correctly but I didn’t understand what is # (at the start) and at the end of the expression. Are not ^ and $ the start/end characters?

preg_match_all('#^/([^/]+)/([^/]+)/$#', $s, $matches);

Thanks

Answer 1

The matched pattern contains many /, thus the # is used as regex delimeter. These are identical

/^something$/

and

#^something$#

If you have multiple / in your pattern the 2nd example is better suited to avoid ugly masking with \/. This is how the RE would like like with using the standard // syntax:

/^\/([^\/]+)\/([^\/]+)\/$/